Bespoke bat surveys

Bespoke bat survey tools, Hammersmith, London

Client: Linden Homes

Objective: Bat surveys and mitigation ahead of planning permission

The redevelopment of a small site at 281 King Street in Hammersmith was proposed by Linden Homes.

The problem

Local residents were protesting about the redevelopment proposal on the basis that bats foraging and commuting over the buildings would be adversely impacted by the proposals and associated lighting. The area is urban with office blocks and residential houses, but nearby Ravenscourt Park and the River Thames provide an extensive network of foraging habitat for bats, linking to the London Wetland Centre and Chiswick Park.

The solution

In addition to carrying out the standard bat surveys, which are required to determine if bats are roosting within the buildings, a bespoke survey was designed to address the residents’ concerns. Automated bat detectors were positioned on the roof between the buildings, and were set to record bat data at key times every night for one month.

We ran the standard and bespoke surveys side by side to minimise the duration of the survey period. In tandem, we recorded existing light levels and assessed these in relation to impact on bats.

The Ecology Consultancy advised on bat-friendly lighting

The Ecology Consultancy advised low-level lighting

The outcome

Bat emergence surveys found roosting bats likely to be absent. The automated detectors recorded four bat species (Leisler’s, noctule, common pipistrelle and soprano pipistrelle) using the site, but at low numbers. We concluded the site was of low value to commuting bats, and negligible potential for foraging bats.

We recommended environmental mitigation in the area because existing street and security lighting levels were considered high. We advised diminished lighting levels and the re-direction of luminescence to reduce the impact on the small numbers of bats passing over or near-by the site.

The specific concerns of residents were addressed, as were the requirements of the Local Planning Authority.

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